bartlett



E. E. BARTLETT.

Patented Aug. 12, 1919.

2 SHEETS-SHEET I.

E. E. BARTLETT.

ARBOR PRESS.

APPLICATION FILED MAR. 7, 1919.

Patented Aug. 12, 1919.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

1 EDWIN E. BARTLETT, OF NASHUA, NEW HAMPSHIRE.

nniaonrranss.

Specification of Letters Patent.

Patented Aug. 12, 1919.

Application fi led lviarch 7, 1919. Serial no; 281,160.

T all whom it may concern Be it known that I, EDWIN E. BARTLETT a citizen of the United States, residing at Nashua, in the county of Hillsborough and State of New Hampshire, have invented certain new and useful Improvements in Arbor- Presses; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates particularly to mandrel or arbor presses in which a pressure applying ram is actuated by means of a manually operable lever through suitable speed reducing mechanism including a pair of shafts which carry pinions engaging a rack on one side of the ram. The speed reduction of the mechanism for actuating the ram in this type of arbor press is approximately in the proportion of 250 to 1, so that the press is capable of being actuated by the operator to apply a considerable amount of With the mechanisms heretofore employed for actuating the ram in this type of arbor press, it has been found that this strain on the shafts tends to distort one of them to a greater extent than the other, so that when the press is employed to apply a maximum amount of pressure, the teeth of the two pinions do not properly engage the rack teeth.

The object of the present invention is to provide a novel and improved mechanism for actuating the ram in the type of arbor press described which retains all the advantages of the prior construction, while doing away with the disadvantages.

The several features of the present invention will be readily understood from the following description and the accompanying drawings, in which Figure 1 is a side elevation looking from the right of the upper portion of an arbor press embodying t e features of the invention in their preferred form;

Fig. 2 is a front elevation;

Fig. 3 is a side elevation looking from the left, and

Fig. 4 is a vertical sectlonal view taken on the line 4-4 of Fig. 1 with the usual hand wheel and hand operated ratchet lever removed.

The embodiment of the invention illustrated in the drawings is provided with the usual vertical ram 6 which is mounted in a suitable bearing 8 in the frame of the ma chine. The ram has rack teeth 10 formed on the rear side thereof which are engaged by a pair of small gears or pinions 12 and 1 1 formed on shafts 16 and 18, respectively. These shafts extend through the head of the machine frame and are j ournaled in suitable bearings 20 therein. A relatively'large gear 22 is secured to the shaft 16 adjacent the outer'end of the right hand bearing 20 for the shaft. A corresponding gear 24 is secured to the left hand end of the shaft 18 adjacent the outer end of one of its bearings. A collar 26 secured to the right end of the shaft 18 cooperates with the gear 24 to prevent lengthwise movement of the shaft. The gears 22 and 21 are capable of being driven in unis0n by means of the usual hand operated ratchet lever 28 which is fulcrumed upon the right end of the shaft 16. The lever '28 carries a downwardly spring pressed pawl 30 which engages a ratchet wheel 32 loosely mounted on the shaft 16. A small gear or pinion 34 is also loosely mounted on the shaft 16 and is secured to the ratchet wheel 32. This pinion operatively engages a relatively large gear 36 secured to the right end of a shaft 38 which extends through the head of the machine frame and is ournaled in suitable bearings therein. The shaft 38 also carries a pinion 40 located between the gear 36 and the frame which operatively engages the gear 22 secured to the shaft 16.

. A corresponding pinion 42 is secured to the ployed to move the ram toward the work and in order to move the ram from the work the usual hand wheel 44 is secured to the left end of the shaft 16, the usual pawl lifting de vice (not shown in the drawings) being employed to lift the pawl during the non-effective strokes of the lever 28.

This construction and arrangement of the parts of the im roved mechanism for actuating the ram, w ich mechanism employs the fewest number of gears possible to accomplish the desired speed reduction, permits the gears 22 and 24: secured to the pinion carrying shafts 16 and 18 to be equally spaced from the longitudinal center line of the rack on the ram, as shown in the drawings. Consequently, a corresponding degree of torsional strain is placed upon the pinion shafts during the actuation of the press so that there is no tendency to distort one of the pinion shafts more'than the other, which insures the pinions engaging and actuating the rack in a uniformly reliable manner i1 respective of the amount of torsional strain placed upon them. Moreover, this construction and arrangement permits both gears 22 and 24 to be placed close to the longitudinal center line of the rack so that the tendency of the actuation of the press to distort the shafts is reduced to a minimum.

The nature and scope of the invention having been indicated-and a press embodyingthe features of the invention having been specifically described, what is claimed is 1. A press of the class described having, in combination, a ram having a rack on one side thereof, a pair of shafts located on the same side of the ram, a pinion carried by each of the shafts and engaging said rack, a gear secured to each of the shafts on opposite ends thereof and equally spaced from the longitudinal center line of said rack, and means engaging said gears to drive said pin ionsin unison.

2. A press of the class described having, in combination, alram having a rack on one side thereof, a pair of shafts located on the same side of the ram, a pinion carried by each of the shafts and engaging said rack, a gear secured to each of the shafts on oppo- Copies of' this patent may be obtained for site ends thereof and equally spaced from --ing-the latter pinions, a gear secured to one end of the latter shaft and in mesh with a pinionvlo'osely mounted on one ofthe shafts carrying the rack engaging pinions and located adjacent the outer face of said gear secured to this shaft, and means for rotating said pinion loosely mounted onthe shaft.

3. A" press of the class described having, in combination, a ram having a rack on one side thereof, speed reducing mechanism for reciprocating the ram, said speed reducing mechanism comprising a pair of shafts, a pinion formed on each of the shafts and engaging said rack, a gear secured to each of the shafts on opposite ends thereof and equally spaced from the longitudinal center line of the rack, and means for rotating said gears in unison,

4. A press of the class described, having, in combination, a ram having a rack on one side thereof, a pair of shafts located onthe same side of the ram, a pinion carried by eachof the shafts and engaging said rack, a gear secured to of the shafts and equally spaced from the longitudinal center line of said rack, and manually operable speed reducing mechanism for driving said gears in unison.

EDWIN E. BARTLETT.

five cents each, by addressing the0ommissionefdf Patents, Washington, n c." 

